Frequency scanning of a leaky wave antenna on a rectangular dielectric-filled waveguide

V. I. Kalinichev ¹, A. A. Babaskin ²

¹ Kotel’nikov Institute of Radio-Engineering and Electronics of RAS

² RF Mtech, Seul, South Korea

 

The paper is received on July 26, 2016

 

Abstract. À leaky wave antenna on the base of a rectangular dielectric-filled waveguide with double transverse slots in the broad wall is considered. Using the earlier proposed method for open radiating periodic structures one can compute the complex propagation constant and the dispersion characteristic of the leaky wave within the eigen modes model. The radiation of -1 space harmonic is analyzed, for which backward and forward radiation regimes take place. These regimes are separated in frequency by a narrow stop band within which the wave stops to propagate. The corresponding radiation angles take negative and positive values relative to the normal to the broad wall. The computed Q values for the considered structure show that the leakage rate in the backward radiation regime is lower than in the forward radiation regime. The presented E field magnitude distributions for the leaky wave inside the unit cell of the slotted periodic waveguide clearly demonstrate different radiation regimes. Besides, the FEM-based driven mode model of a finite length slotted waveguide antenna with equally spaced pairs of transverse slots is developed. Using this model it is possible to compute the S-parameters and radiation patterns at different frequencies in the band of interest. Two values of the dielectric permittivity of the filling material were considered. It is shown that for the larger value of the dielectric permittivity ε=9 the antenna can provide the scan range from -48 to +28 degrees relative to the normal to the broad wall at the frequencies from 8.5 to 10.5 GHz. For the lower value of the dielectric permittivity ε=2.25 the antenna scans in the range from -18 to +13 degrees at the same frequencies. The main beam radiation angles for the slotted waveguide antenna obtained in the driven mode solution agree perfectly with the directions of radiation determined from the dispersion diagram.

Key words. Leaky wave antenna, dielectric-filled waveguide, double transverse slots, frequency scanning. 

References

1. Walter C. H. Traveling wave antennas. McGraw-Hill. 1965. 429 p.

2.Voskresensky D. I., Granovskaya R. A., Davidova N. S. and others. Antenni i ustroystva SVCH (Proektirovanie fazirovannih antennih reshetok)/ [Antennas and microwave devices]. Moscow, Radio i Svyaz Publ. 1981. 432 p. (In Russian)

3. Kaloshin V. A. Millimeter-wave antennas. Zarubezhnaya radioelektronika, 1984, No. 11, pp. 97-106. (In Russian)

4. Josefsson L. A waveguide transverse slot for array applications. IEEE Trans. Antennas and Propagation, 1993, Vol. 41, No. 7, pp. 845-850.

5. Joubert J. A transverse slot in the broad wall of inhomogeneously loaded rectangular waveguide for array applications. IEEE Microwave and Guided Wave Letters, 1995, Vol. 5, No. 2, pp. 37-39.

6. Blinova N. K., Lyakhovsky A. A., Yatsuk L. P. Multielement systems of double slots in rectangular waveguide with partial dielectric filling. Proc. of the 5^th International Conference “Ultrawideband and Ultrashort Impulse Signals (UWBUSIS)”. Sevastopol, Ukraine, 2010, pp. 82-84. DOI: 10.1109/UWBUSIS.2010.5609103. IEEE

7. Abdullin R. R., Knyazev S. T., Shabunin S. N. Using Green’s function method for the leaky-wave antenna analysis based on a dielectric partially-filled

rectangular waveguide with transverse slots. 23rd Int. Crimean Conference “Microwave & Telecommunication Technology” (CriMiCo’2013). Sevastopol, Crimea, Ukraine, 2013, pp. 580-581, IEEE. (In Russian)

8. Liu J., Jackson D. R., and Long Y. Modal analysis of dielectric-filled rectangular waveguide with transverse slots. IEEE Trans. Antennas and Propagation, 2011, Vol. 59, No. 9, pp. 3194-3203.

9. Modern antenna handbook, edited by Balanis C. A. New York, John Wiley & Sons. 2008. 1680 p.

10. Caloz C., Itoh T. Electromagnetic metamaterials: transmission line theory and microwave applications. The engineering approach. New Jersey, John Wiley & Sons. 2006. 352 p.

11. Dong Yu., Itoh T. Composite right/left-handed substrate integrated waveguide and half mode substrate integrated waveguide leaky-wave structures. IEEE Trans. Antennas and Propagation, 2011, Vol. 59, No. 3, pp.767-775.

12. Kalinichev V. I., Babaskin A. A. A method of calculating the leaky-wave propagation constant in slotted waveguides. Zhurnal Radioelektroniki - Journal of Radio Electronics, 2015, No. 7. Available at http://jre.cplire.ru/jre/jul15/2/text.pdf (In Russian)

13. Vainstein L. A. Elektromagnitnie volni. [Electromagnetic waves]. 2^nd  edition. Moscow, Energiya i Svyaz Publ. 1988. 440 p. (In Russian)